Most cable network systems are coaxial-based broadband access systems that may take the form of all-coax network systems, hybrid fiber coax (HFC) network systems, or RF over glass (RFOG) network systems. Cable network system designs typically use a tree-and-branch architecture that permits bi-directional data transmission, including Internet Protocol (IP) traffic between the cable system head-end and customer locations. There is a forward or downstream signal path (from the cable system head-end to the customer location) and a return or upstream signal path (from the customer location back to the cable system head-end). The upstream and the downstream signals occupy separate frequency bands. In the United States, the frequency range of the upstream band is from 5 MHz to 42 MHz, 5 MHz to 65 MHz, 5 MHz to 85 MHz, or 5 MHz to 204 MHz, while the downstream frequency band is positioned in a range above the upstream frequency band.
Customer locations may include, for example, cable network system (e.g., CATV) subscriber's premises. Typical signals coming from a CATV installation at the subscriber's premises include, for example, set top box DVR/On Demand requests, test equipment data channels, and Internet Protocol output cable modem carriers defined by the Data Over Cable Service Interface Specification (“DOCSIS”), which is one communication standard for bidirectional data transport over a cable network system.
Egress or leakage from the cable network system results from flaws in the cable network system that provide points of ingress for noise, which can reduce the quality of service of the system. Service operators have utilized two basic types of leakage detection gear to locate such points of ingress. One type of gear utilizes a signal level meter with an antenna designed to receive signals in the cable network system band. A maintenance/service technician walks around a subscriber's premises monitoring the signal level meter to identify flaws in the wiring and network devices at the subscriber's premises.
The other type of gear is so-called “truck-mounted” units, which are mounted in vehicles that are driven along the data lines and nodes of the cable network system, generally by maintenance/service technicians, to monitor leakage along the cable network system.
One example test procedure and associated instrumentation for locating leakage is shown and described in U.S. Patent App. Pub. No. 2017/0251207, which is expressly incorporated herein by reference.